To parents, there is no force known to science as powerful as the repulsion between children and vegetables.

Of course, just as supercooling fluids can suspend the law of electrical resistance, melting cheese can suspend the law of vegetable resistance. This is sometimes known as the Pizza Paradox. There is also the Edamame Exception, but this is generally considered to be due to the Snack Uncertainty Principle, by which a crunchy soybean is and is not a vegetable simultaneously. But when melty mozzarella conditions don’t apply, the law of vegetable repulsion would appear to be as immutable as gravity, magnetism or the equally mysterious law of child-godawful mess attraction.

In a new paper in Psychological Science, however, Sarah Gripshover and Ellen Markman of Stanford University have shown that scientists can overcome the child-vegetable repulsive principle. Remarkably, the scientists in question are the children themselves. It turns out that, by giving preschoolers a new theory of nutrition, you can get them to eat more vegetables.